Histological and histometric findings in patients with chronic fatigue syndrome
| Authors | No of patients biopsied/studied | Histology | Histometry | Other findings and comments |
|---|---|---|---|---|
| Behan et al(1985)11 | 20/50 | 15/20 scattered necrotic fibres | Moderate type 2 fibre predominance and hypertrophy in all | Conspicuous increase in peripheral mitochondria and occasional tubular inclusions. 30/40 abnormal jitter on SFEMG, 6/6 abnormal magnetic resonance spectroscopy of muscle |
| Byrne et al(1985)12 | 2/2 | Normal | Type 2 atrophy in both consistent with disuse | Mild reduction in state 3 respiration on polarography of isolated mitochondria |
| Byrne and Trounce (1987)13 | 11/11 | Minicore change in one case | 10/11 normal or mild 2b fibre atrophy | Glycolytic and mitochondrial enzymes normal in vitro |
| Karpati et al(1990)14 | ? | Slight excess of central myonuclei, scattered small fibres in most. No inflammation | Striking MHC class I expression in 2 cases | |
| Behan et al(1991)15 | 50/50 | 3 cases occasional necrotic fibres. 2 cases tiny inflammatory foci. 4 cases regenerative changes. 25 cases prominent mitochondria on Gomori stain | 39/50 mild and focal (6 cases) to severe and diffuse (33 cases) type 2 atrophy. 4 cases type 1 atrophy | 40/50 (80%) cases showed structural mitochondrial abnormalities |
| Grau et al(1992)16 | 20/20 | 9/20 non-specific abnormalities, including scattered small or necrotic fibres, abnormal oxidative enzyme staining, focal myofibrillar loss | 3/20 type 2 hypertrophy | 0/20 MHC class I expression |
| Preedy et al(1993)17 | 23/23 | 2 cases had occasional split fibres, 2 others centronuclear chains | 3/20 type 2 atrophy, 5 others hypertrophy of one or both fibre types | Significant reduction in muscle RNA/DNA composition (15%) but not muscle protein/DNA ratio |
| Edwards et al(1993)18 | 74/74 | Non-specific abnormalities in 81% of cases | 27% low prevalence, 12% high prevalence of type 1 fibres, 5/74 fibre atrophy or hypertrophy | Similar abnormalities in 1/3 of normal control biopsies, TA studied in most cases |
| Connolly et al (1993)10 | 26/35 | Non-specific abnormalities in 9/10 cases with prominent myalgia cf. 3/16 other CFS cases | Abnormal biopsy findings in CFS cases with prominent myalgia associated with increased fibre density on SFEMG, EDC biopsied in all cases |
SFEMG=Single fibre electromyography, TA=tibialis anterior, EDC=extensor digitorum communis.